Installation for fire fighting and sprinkler

ABSTRACT

The invention relates to an installation for fire fighting, using a number of automatically released sprinklers. The invention also relates to a sprinkler to be used in the installation. With the aim of conserving extinguishing liquid, reducing the size of the drive unit of the installation intended for the procedure and providing an active installation that is released directly by a sprinkler, the installation comprises a number of electric positive and negative wires, which have been arranged to a scanning device comprising breakers (+A-+E, -13, --19) for each positive and negative wire, whereby said wires form an electric net where positive and negative wires are electrically connected via sprinklers respectively comprising individual breakers (K), whereby each sprinkler is arranged to open its breaker (K) upon the release the sprinkler in question and to thus interrupt the connection between the respective positive and negative wire, whereby the scanning device, upon establishing the interrupted connection and the position of the released sprinkler, is arranged to release according to a plan the sprinklers adjacent to said position by closing according to said plan the breakers (+A-+E, -13, --19) of the scanning device.

The present invention relates to an installation for fire fighting,comprising a number of circuits with sprinklers, whereby each circuit isarranged to automatically be separately switched on in the event of afire after release of a sprinkler in the circuit at the site of thefire. The invention also relates to a sprinkler comprising a housing andan inlet at the side of the housing to a central channel with a spindlein a sliding or almost sliding contact with the channel wall, whichsprinkler is intended to be employed in said installation for firefighting.

In previous known installations of this kind, e.g. an installationmonitoring a vehicle deck on a car ferry, the monitored area in questionhas usually been divided into a number of circuits or sections that canbe separately activated and that each can be relatively extensive. Inmodern car ferries having a width of, for instance, 40 meters, a sectionhas normally extended across the entire width of the ship and about 20meters along the length of the ship. Since a fire can very well breakout at or near the joint between two sections, the possibility tosimultaneously activate two sections has been considered necessary. Thisresults first of all in a considerable waste of extinguishing liquid andalso requires extremely powerful units for the delivery of theextinguishing liquid. The complete installation becomesunproportionately expensive.

German Offenlegungsschrift 2,548,850 discloses a fire fighting equipmentcomprising several sprinklers, the equipment being arranged--in order toprovide optimum fire fighting with a relatively small amount ofextinguishing medium--to release only part of all the sprinklers of theapparatus. The circuit, or those of the sprinklers, that is/are releasedis/are located in the immediate vicinity of the fire detector producingthe signal. One problem of this known fire fighting equipment is thatconventional fire detectors that are separate from the sprinklers areused. The fire detector may produce a false signal, as a result of whichthe wrong fire fighting circuit is switched on. A false signal may occurwhen the fire detector reacts to smoke that is drifting from a distantsite of fire as a result of strong air currents. As a result, the firedetector causes such valves to open that convey extinguishing liquid toa fire fighting circuit that is not located near the fire. This problemis further aggravated by the fact that the fire detectors are typicallyrelatively few in relation to the number of sprinklers. Another problemof this known fire fighting equipment is its complicated construction.

A fire fighting system which is arranged to control a number of firefighting functions that are arranged in the same fire fighting line,such as the closure of fire-proof doors and the connecting ofextinguishing devices, is known from German Offenlegungsschrift2,533,354. In this system, separate fire detectors are also employed,which involves an uncertainty factor as explained above.

The object of the present invention is to provide a new fire fightingsystem which solves the above problems.

To achieve this object, the installation is characterized in that itcomprises a number of electric positive and negatives wires, which havebeen arranged to a scanning device comprising breakers (+A-+E, -13,--19) for each positive and negative wire, whereby said wires form anelectric net where positive and negative wires are electricallyconnected via sprinklers respectively comprising individual breakers K,whereby each sprinkler is arranged to open its breaker K upon therelease of the sprinkler in question and to thus interrupt theconnection between the respective positive and negative wire, wherebythe scanning device, upon establishing the interrupted connection andthe position of the released sprinkler, is arranged to release accordingto a plan the sprinklers adjacent to said position by closing accordingto said plan the breakers (+A-+E, -13, --19) of the scanning device.Preferably, the scanning device is arranged to release the desirednumber of adjacent sprinklers via the same electric wires that are usedfor the scanning, by conducting an electric current through a heatingcoil placed around a heat-sensitive release bulb of the respectivesprinklers in order to heat the release bulb. The sprinklers of thesystem comprise a heat-sensitive release bulb which suitably can be aconventional vial.

The sprinkler according to the invention is characterized in that thespindle is arranged in said contact on both sides of the inlet for atleast partial balancing of the fluid pressure of the inlet, whereby thespindle comprises an electricity conducting rod for electricallyconnecting a positive pole of the sprinkler to a negative pole of thesprinkler, which rod is arranged to interrupt the electric connectionbetween the positive pole and the negative pole when the spindle ismoving due to the sprinkler changing from the standby state to thereleased state. Preferably, the spindle is arranged, with a helicalspring, in the central channel and the rod is arranged to be displacedwith the movement of the spindle. As a result of the balancing of thefluid pressure, the spindle does not exert a great force against therelease bulb, which could easily destroy the latter. The balancing ofthe fluid pressure can be complete, whereby the fluid pressure does notstrive to press the spindle against the release bulb, or partial,whereby only a less powerful force which does not break the release bulbis applied against the latter.

The concept of the invention is in principal that at least a part,preferably all, of the sprinklers of the installation, which sprinklerscomprise individual breakers reacting on fire, are continuously,repeatedly, and individually scanned in order to determine the positionof a sprinkler that has been released as a result of a fire and that apredetermined number of sprinklers or spray heads in the surrounding arethen released in one or several steps. Thus, the actual sprinkleractively releases the other sprinklers in the immediate vicinity of thefire. The scanning device establishes or detects an open circuit as thecircuit is not carrying current and simultaneously determines theposition of the sprinkler that has interrupted the circuit. Next, thescanning device releases the desired number of sprinklers nearby via thesame electric wires that are used for said scanning. As a result, thenumber of electric wires can be significantly reduced. The voltagesource can be a separate battery, the current of which heats the heatingcoils positioned around the heat-sensitive release bulb of therespective sprinklers.

The sprinklers and/or the spray heads of the installation can thus bearranged, e.g. in the case of the vehicle deck mentioned above, as anintegral net without a definite division into sections; a section thatis adapted to each fire position but that is considerably smaller thanthose of previous solutions is automatically activated, whereby on theone hand the waste of extinguishing liquid, especially during theusually critical initial stage of the fire fighting, can besignificantly reduced and on the other hand the drive unit of theinstallation can be, to the corresponding degree, smaller dimensioned.

In the following, the invention will be described in detail withreference to the preferred exemplary embodiments illustrated in theenclosed drawing:

FIGS. 1-3 show schematically part of a larger installation at a firststage with a single sprinkler released as a result of a fire that hasbroken out, and sprinklers additionally released in a second and a thirdstage as planned.

FIGS. 4 and 5 show a longitudinal section of a preferred embodiment ofsprinklers that can be used in the installation and that are in thestandby state and active or released state, respectively.

In FIGS. 1-3, the sprinklers of the installation are arranged in anelectric net or a grid comprising a number of positive wires A-E andnegative wires 13-19 running laterally to the positive wires, in eachcase between a positive wire and a negative wire so that the position ofthe respective sprinklers can be expressed by means of the positive andnegative wires; A13 . . . C15 . . . E19.

As regards the respective wires, the connecting and disconnecting of ascanning device is indicated by means of breakers +A . . . +E and -13 .. . -19. A breaker K indicates the state of the respective sprinklers;the closed breaker K, which, e.g. in the case the sprinklers A13 and E19in FIG. 1, indicates an inactive or unbroken state, which can also becalled a standby state, and an open breaker K, which, e.g. in the caseof the sprinkler C15 in FIG. 1, indicates a released or an activatedstate. An arrow P for a sprinkler with a closed breaker K indicates aninitiated active electric release of the sprinkler, i.e. the sprinklersB14 . . . B16, C14 and C16, D14 . . . D16 in FIG. 2, A14 . . . A16, andE14 . . . E16 in FIG. 3.

The sprinklers can be individually scanned by connecting the positivewires A-E in proper order and connecting the negative wires 13-19separately for each positive wire in proper order. Available devices arethus capable of scanning, e.g. an installation for such a car ferry thatwas mentioned earlier, in about a second.

In FIG. 1, all the breakers +A . . . +E and -13 . . . -19 are open, asis the breaker K of the sprinkler C15, which indicates that a fire hasreleased the sprinkler C15 after the scanning last passed the sprinklerC15, the scanning being in progress outside FIG. 1. The next time thescanning reaches the positive wire C, and the breaker +C is closed, andalong the positive wire C reaches the negative wire 15, and the breaker-15 is closed, it is established that the scanning circuit +C . . . C15.. . -15 is open and that there is a fire at C15.

As shown in FIG. 2, the positive wires B and D and the negative wires 14and 16 are then automatically also connected by means of the scanningdevice for an active electric release of the sprinklers B14 . . . B16,C14 and C16, and D14 . . . D16 that are located around the sprinklerC15. As shown in FIG. 3, when these sprinklers have been activated, athird step in which, for instance, the sprinklers A14 . . . A16, and E14. . . E16 are actively released can be initiated.

FIGS. 4 and 5 show a section of an embodiment of a sprinkler, which maywell be used in the installation according to FIGS. 1-3 but which,naturally, also can be used independently in other applications. Thesprinkler is generally marked with 30, its housing or frame with 31 andits liquid inlet with 32. The liquid inlet 32 leads to a central channel33 which branches in a number of, e.g. nine, oblique nozzles 34, ofwhich every third may have a jointly fed additional nozzle 35 in theusually downwards directed bottom of the sprinkler. A holder 36 for aconventional heat-sensitive release bulb 37, e.g. a glass vial thatexplodes at an elevated temperature, is also mounted to the bottom ofthe sprinkler.

In the central channel 33 of the sprinkler, a spindle 38 is arranged toslide, which spindle at the top at liquid inlet 32 has a sleeve 38a,which is followed by a piston-like part 39 sealed against the sprinklerhousing 31, the part being called piston hereinbelow, which part isfollowed by a narrower distribution part 40 provided with orifices 41,which distribution part 40 finally ends in an end part 42 insulatinglysealed against the vial holder 36.

An axial channel 43 runs through the sleeve 38a, the piston 39 and thedistribution part 40 and, in the part thereof that runs in the sleeve38a, a helical spring 44 is fixed with its lower end according to theFigures resting on the piston 39 and with its upper end at least instandby state according to FIG. 4 resting on an insulating piece 45fixed in a head 46 screwed into the housing 31. An electricityconducting rod 47 runs though the channel 43, the upper end of the rod47 in FIG. 4 being in an electricity conducting but disengagable contactwith a conducting element 48 which is connected to a positive pole 60.The lower end of the rod 47 is in a corresponding contact with the endpart 42 of the spindle, which in addition to being insulated from thevial holder 36 also is insulated from the spindle parts 38-40 that arein contact with the housing 31 by means of an insulating casing 49, andfrom direct contact with the housing 31 by an air gap. A heating coil 50is placed around the release bulb 37, which coil is in conductingcontact with the end part of the spindle and the vial holder 36, whichis electrically connected by means of a conducting element 51 runningthrough the housing 31 to a negative pole 61. The holder 36 and theelement 51 are insulated from the housing 31 by means of insulatingcasings 52 and 53 and from the part of the element that runs through thehousing by means of an air space.

The force of the spring 44 and the ring area of the piston 39, which isunder the influence of the fluid pressure in the inlet 32, are adjustedin such a way that the spindle 38 in the standby state of the sprinkleraccording to FIG. 4 does not crush the vial 37 when the vial has anormal temperature. The spindle 38 is thus arranged to at leastpartially balance the fluid pressure of the inlet 32. If the sleeve 38aslides against the wall of the channel 33 so that contact isestablished, a complete balance of the fluid pressure in the inlet 32 isachieved; only the spring 44 presses the spindle. The upper end of thesleeve 38a lies snugly between the insulating piece 45 and the head 46;there is no connection for the liquid from the inlet 32 to the spindlechannel 43 and further to the nozzles 34 and 35; however, an electricityconducting connection does exist from the positive pole 60 through theelement 48, the rod 47, the end part 42 of the spindle, the heating coil50, the vial holder 36 and the element 51 to the negative pole;corresponds to the closed breaker K, FIGS. 1-3. The scanning is so rapidthat the heating coil 50 is not heated.

If the vial 37 as a result of hot gases or active heating by means ofsufficient current through the heating coil 50, explodes, the force ofthe spring 44 knocks down the spindle 38 as a block against the vialholder 36, as illustrated in FIG. 5. In the event that a small imbalanceof the fluid pressure prevails at the inlet at the nozzle, the forceknocking down the spindle is constituted of said spring force added withthe small additional downward force which the partial imbalance in thefluid pressure exerts on the spindle. The spindle sleeve 38a movessufficiently far in order to provide a connection for the liquid fromthe inlet 32 to the channel 43 and further to the nozzles 34 and 35,preferably with high pressure and penetrating concentration inaccordance with the patent application PCT/FI92/00155. Furthermore, theend 47a of the rod 47 comes off from its insertion 48a, the other end ofthe rod comes possibly off from its corresponding insertion in the endpart 42. This corresponds to an open breaker K, FIGS. 1-3.

I claim:
 1. An installation for fire fighting, comprising a number ofcircuits with sprinklers, each circuit being arranged to automaticallybe separately switched on in the event of a fire after release of asprinkler in the circuit at the site of the fire, a number of electricpositive and negative wires, which have been arranged to a scanningdevice comprising breakers (+A-+E, -13, --19) for each positive andnegative wire, wherein said wires form an electric net where positiveand negative wires are electrically connected via sprinklersrespectively comprising individual breakers (K), each sprinkler beingarranged to open its breaker (K) upon the release of the sprinkler inquestion and to thus interrupt the connection between the respectivepositive and negative wire, and wherein the scanning device, uponestablishing the interrupted connection and the position of the releasedsprinkler, is arranged to release according to a plan sprinklersadjacent to said position by closing according to said plan the breakers(+A-+E, -13, --19) of the scanning device.
 2. An installation accordingto claim 1, comprising sprinklers with a heat-sensitive release bulb(37), wherein the scanning device is arranged to release the desirednumber of adjacent sprinklers via the same electric wires that are usedfor the scanning, by conducting an electric current through a heatingcoil (50) placed around the heat-sensitive release bulb (37) of therespective sprinklers in order to heat the release bulb.